call

# File actionpack/lib/action_dispatch/middleware/public_exceptions.rb, line 25
    def call(env)
      request      = ActionDispatch::Request.new(env)
      status       = request.path_info[1..-1].to_i
      content_type = request.formats.first
      body = { status: status, error: Rack::Utils::HTTP_STATUS_CODES.fetch(status, Rack::Utils::HTTP_STATUS_CODES[500]) }

      if env["action_dispatch.original_request_method"] == "HEAD"
        render_format(status, content_type, "")
      else
        render(status, content_type, body)
      end
    end